I bought Batman Arkham Knight Premium Edition for €3.89 and got...

I tried it and only gave me premium edition.

Maybe it's this https://steamdb.info/sub/71644/apps/

if i dont remember badly, for those who pre.ordened the game its gives all the collection, becouse when the game comes out it have a lot of bugs, something like that was, i dont remember exactly how it was.

so, your key Is a "pre.order game key" or you buy it before nov.2015

check the forums On steam, there Is info related there.

sorry for my basic english

edit: its a great game, by the way

I can confirm seller 'Exoncore' drops key which redeems this sub:

| Status: OK/NoDetail | Items: [71644, Batman: Arkham Knight Premium Edition]

i did not get the rest. only batman premuim :/

https://www.gamespot.com/articles/batman-arkham-knight-returns-to-pc-with-free-bonus/1100-6431801/

14. Reselling keys and links to reseller stores. Do not use our site to resell keys, and do not post offers from stores which allow third parties to resell their keys or gifts. For example, do not ask others if they are interested in buying your leftover keys from a recent bundle purchase, or link to keys for sale on sites such as Kinguin, G2A, or Eneba.

Do not link to grey market sites. You can ask from where this weird sub came from, you can't link in any way to grey market site.

I will close this thread till you edit your OP post. You can then make ticket in other category to re-open thread.